stephens



(No Model.) 2 Sheets-Sheet 1.

R. & W. O. STEPHENS. MACHINERY 'FOR DRILLING BOOKS.

Patented Apr. 21, 1891.

(N0 Model.) 2 Sheets-Sheet 2,

R. & W. U. STEPHENS. MACHINERY FOR DRILLING ROCKS.

No. 450,921. Patented Apr. 21, 1891.

Ill

WLtmSas.

NITE STATES RICHARD STEPHENS AND VILLIAM CHARLES STEPHENS, O1 POOL, ENGLAND.

PATENT ()FFICE.

MACHINERY FOR DRILLING ROCKS.

SPECIFICATION forming part of Letters Patent No. 450,921, dated April 21, 1891.

Application filed July 29, 1890. Serial No. 860,802. (No model.)

admitting steam or other motive fluid to the cylinder is operated directly from the pistonrod by means of a protuberance or enlargement thereon, instead of indirectly through the medium of a cam or tappet, as has frequently heretofore been the case. The said valve, which is in the form of a plate, having suitable openings and recesses therein to form ports, is mounted upon a stud, bolt, or pin passing through the valve chamber, and adapted to oscillate on the said bolt or the like under the action of the protuberance upon the piston-rod, the said ports in the valve during the movement thereof being caused to correspond with suitable inlet and exhaust ports formed in the walls of the valve-chamber. The valve is advantageously faced upon both sides, so that when it becomes worn upon one side it may be reversed. In order to provide for the rotation of the pistonrod, we employ two clutch-disks, one of which is secured to the head of the twist-bar and adapted to rotate therewith, while the other is held against rotation and is normally pressed toward the first-mentioned clutch by means of a spring.

To enable our invention to be fully understood, we will describe the same, with reference to the accompanying drawings, in which Figure 1 is a longitudinal section of a rockdrill provided with our improvements. Figs. 2 and 3 are transverse sections of the same on the lines w a: and y g respectively. Fig. 4 is a view of the face against which the valve works, and Fig. 5 is a view of the valve. Figs. 6 and 7 are sections of the valve on the lines to to y 1 respectively. Fig. 8 is a side view of the clutch-disks for causing rotation of the piston-rod, and Fig. 9 is a face view of one of the said disks.

Similar letters of reference indicate corresponding parts in the several figures of the drawings.

a indicates the cradle, and b the cylinder, adapted to slide in the same and to be moved by the screw 0.

cl is the piston-rod, and c e are the pistons.

f is the valve-chest, provided with two pairs of ports 9 g 72. h, the former of which establish communication between the interior of the valve-chest and the atmosphere, and the latter of which communicate by means of passages t' a" with the two ends of the cylinder b.

j is our improved valve, which is provided with a pair of ports or openings 7.: 7e, )assing entirely through it, and on each side with a pair of recesses Z Z, the saidvalve being carried upon abolt or pin m,passin'g through the valve-chest and being oscillated thereon by means of the protuberance n on the pistonrod between the pistons e e.

o 0' are the clutch-disks, and 13 is the twistbar, which at one endis provided with an extension (1 of smaller diameter than the twistbar proper, the said extension being supported at its end in a bearing q in the cylindercover r. The clutch-disk 0 is firmly secured to the extension q, so as to rotate with the twist-bar, while the clutch disk 0 passes freely over the said extension. The said disk 0 is held against rotation by means of lugs 0 entering corresponding recesses in the cylinder-cover, but is free to slide on the said extension.

s is a spring which normally tends to press the disk 0 into engagement with the disk 0.

The operation of the apparatus hereinbefore described is as follows: Assume the pistons to be at their innermost position and the opening L to be in coincidence with the port 7t, communicating with the rear end of the cylinder through the passage 4;. If now air or steam is admitted into the valve-chest-for instance, through the aperture tthe air or steam will act upon the piston e and force the same, together with the rod (Z, forward.

IOG

By the time the forward position is reached the protuberance n, by acting upon the under side of the valve j, will have oscillated the same sufficiently far to bring the opening 7c into coincidence with the port It and the recess l (adjacent to the valve-face) over the ports 9 h, so that the compressed air or steam will then enter the front end of the cylinder through the passage'i and act upon the piston e to force the same, with the rod cl, backward, the air or steam in the rear end of the cylin- (ler being at the same time forced out through the passage '6, the port h, the recess l, and the port g, and so on, the operation being repeated at each stroke of the piston. During the outstroke of the pistons, when the drill is driven the twist-bar p is caused to rotate, the teeth of the disk acting upon the teeth of the disk '0 in such a manner as to force the latter disk backward. On the instroke of the pistons, however, during the withdrawal of the drill the teeth of the two disks being in engagement, the pistons and piston-rod are caused to rotate upon their axis in a well-known manner.

The object of constructing the valve j with two sets of recesses l l on opposite sides thereof is that when the valve is worn upon one face it can be reversed to work upon its other face.

Having now particularly described and as certained the nature of the said invention and in what manner the same is to be performed, we declare that what we claim is 1. In a rock-drill, the combination, with 3 the steam-chest provided with a valve-seat at one side having inlet and exhaust ports, of a flat valve having one face in engagement with said valve-seat, said valve being narrower than the steam-chest and provided with ports 40 on both of its faces corresponding to those of the valve-seat, whereby said valve will be worn on one face only when in operation and may be reversed to place the other face in engagement with said valve-seat.

2. In a rock-drill, the combination, with the steam-chest having a valve-seat at one side of the same provided with inlet and exhaust ports, of a valve of less width than the steamchest, having one face in engagement with said valve-seat, said valve being provided with similarly-arranged ports on both of its faces corresponding to said valve-seat ports, extending entirely through said valve, andadapted to be used when either face is in engagement with said valve-seat, whereby said valve may be reversed when one face is worn, substantiall y as described.

RICHARD STEPHENS. WVILLIAM CHARLES STEPHENS.

Witnesses:

CHARLEs VIVIAN THoMAs,

Oamborne, Cornwall, Solicitor. ARTHUR ABRAHAM RICHARDS,

Cambornc, Cornwall, Sol'lcitors Clerk. 

